Much of the construction of buildings in the industrialized world, particularly in the United States, is of two types, wood frame and various kinds of material, including wood to cover the framework, or steel, usually taken in combination with concrete in the form of prestressed concrete for framing and a variety of other materials to cover the same, frequently concrete block. On larger buildings, a prestressed concrete frame may be covered by glass, marble, stone, or the like. In all of the above cases, insulation, which has become ever more important in an increasingly energy conscience world, is frequently supplied as a separate layer interiorly of the outside structure above-described. When the covering material is concrete block, insulation in at least the exterior walls is frequently omitted.
In order to achieve economies in the cost of construction, various efforts have been made to utilize pre-fabricated materials. Of course, the ultimate in pre-fabrication is with mobile homes which are simply transported to the residence site, and usually then permanently fixed to a foundation. Other types of pre-fabricated or partially pre-fabricated construction methods are also well known such as A frame homes that are frequently used in rural areas as vacation retreats. There have also been very sophisticated structures such as geodesic dome type structures of a type advocated by the well known American inventor Richard Buckminster Fuller. Examples of United States patents of this species either by Fuller or his associates are U.S. Pat. No. 2,682,235 for a geodesic dome, U.S. Pat. No. 2,881,717 for a paper board dome, U.S. Pat. No. 2,905,113 for a plydome, U.S. Pat. No. 2,914,074 for a catenary (geodesic tent), and other similar references such as U.S. Pat. Nos. 3,063,521, 3,139,957, 3,197,927, 3,203,144, and 3,810,336.
Another reference which pursues the notion of a building component utilizing a panel is Zeihbrunner, U.S. Pat. No. 4,646,502 which teaches a panel construction element and building construction system employing such elements. That reference illustrates a profile frame and a filler material with cover panels that cover both the filler material and the profile frame. The frame includes a complex cross-section of a type fabricated using an extrusion, which, in turn, leads to a substantially more expensive structure than that provided by the present invention without the interlocking advantages of the framing with the filler or polymeric material of the present invention.
Similarly, efforts have been made to provide modular building components which produce building walls combining the coverage of area with insulation benefits. Several of these include two patents to Meyerson, U.S. Pat. Nos. 4,769,963 and 5,086,599, both of which involve utilizing an expanded polymeric material taken in combination with aluminum sheet to produce a building panel with excellent insulation properties in a light weight construction component. To the extent that an expanded polymeric material is utilized in these references, they bear some resemblance to the present invention. However, the resulting walls lack any significant structural strength because they are merely the combination of flat and folded aluminum or similar type material in combination with the expanded polymeric material.
Nemmer, et al., U.S. Pat. No. 4,633,634, issued on Jan. 6, 1987, discloses a building side wall construction panel and method. Nemmer includes foam cores connected edge to edge by connecting studs, the studs being two C-shaped channels welded back-to-back. To assemble Nemmer, the studs are secured upright and the foam cores are slid vertically downward into the open C-shaped sides of the studs. A problem with the Nemmer method is that a workman would have to carry tall and possibly unwieldy foam cores to roof level and try to jam their edges into and all the way downward along the stud C-channels to the level of the foundation. This precarious procedure is difficult and places the workman at risk. The double C-shape stud design makes it impossible for the workman to set the cores individually into place from ground level.
Switzerland Patent Number 396,368 teaches an interior wall panel assembly. The back-to-back C-shaped studs require either the procedure set forth in Nemmer where cores are forced downward from roof level, or pre-fabrication of the entire wall in a horizontal plane followed by tilting the wall upright. A complete wall would be heavy and dangerously cumbersome for one or even several workmen to lift upright and position properly. Such a complete wall, if assembled off site, would also be prohibitively bulky and unwieldy to transport.
A rough translation of Switzerland patent 396,368 indicates that it discloses an interior panel which is not load-bearing. "It is quite known to use (provide) gauge frame and panel elements to build interior walls." Switzerland '368 patent, line 1. There is apparently no teaching that the panels (11, 12, 13, 14) are "rigid", and indeed they would not need to be rigid to function as non-load-bearing interior dividers or wall panels. The panels are formed of rectangular foam cores having channel members secured along the core edges. The channel members have a cross-section like those of Nemmer, except that ledges are provided along the longitudinal edges of the C-shaped channels. The ledges are fit into grooves in core faces near core edges, but these ledges would not necessarily retain the insulation core against buckling under vertical compression loading.
The Switzerland channel flanges are revealed to be very flexible and loose in the groove, and indeed too flexible and loose to be capable of retaining the core under vertical loading. Switzerland FIG. 2 shows a composite panel wall only partially assembled, which is described as a "dividing wall in building procedure". Two of the individual cores do not yet have channel members on their top edges. One can see the empty groove along the top edge of each. Yet to complete the wall, such a top channel member must be inserted on each of those top edges. A top channel member cannot be slid into the grooves from the side of the panel, because it is blocked by vertical members 30, 40 and 50. The only way to do so at this stage of the construction, without taking the wall apart again, would be to spread the channel flanges apart to fit over and around the top edge of the particular core. Then the flange walls would be released to resiliently snap into the core engaging grooves.
Given that this approach is the only direct way to make progress on the completion of this wall, this must be the intended assembly procedure. The top channel flanges are, presumably, of the same material and strength as the side channels. If the channel flanges are so soft and flexible that they can be readily spread apart for installation, the channel flanges are clearly too soft and flexible to retain the core against buckling under the vertical compression loading typical of outer wall panels. If the core grooves are wide enough to let the channel ledges pivot down and around into them, they are too wide to securely retain the ledges under core loading. The flanges would simply spring apart and let the core buckle and fail. Of course, the Switzerland channel flanges do not have to carry a load, since they are apparently part of an interior wall structure.
An additional reference is Olton, U.S. Pat. No. 3,271,919, which teaches the use of a flanged channel disposed in opposed and parallel grooves which is used as a door edge protector. However, this reference does not teach load-bearing capability, insulation properties, nor especially the synergistic effect achieved by a composite of materials in an interlocking relationship that makes use of the highly specific qualities of each material, i.e., the compressive strength of the rigid insulation core to maintain the positional integrity of the steel of the vertical member, avoiding lateral deflection thereof, and the steel preventing buckling of the lateral portions of the rigid insulation core.
The present invention relates to a unique composite assembly that may be utilized for the construction of walls, roofs, and flooring, for a variety of structures and buildings. The preferred materials are steel for structural strength in a very specific interlocking relationship with an expanded polymeric material such as medium density polystyrene or polyurethane. The steel provides strength in both tension and compression, while the expanded polymeric material provides thermal and sound insulation and substantial support in compression. The combination, therefore, provides a structural strength that is believed to be absent from the Meyerson references while at the same time providing the high insulation effects that these Meyerson references would be expected to provide, as well as having the advantage of low cost resulting in part from pre-fabrication and the ability to utilize the same in combination with external and internal facing materials that provide aesthetics, protection from the elements, functionality, some additional insulation, and minimal construction labor. Indeed, the present invention produces an excellent substitute for concrete block when the same is used with a prestressed concrete frame, and with the optional exterior and/or interior surfaces, can also replace the materials normally applied to the exterior and/or interior of concrete block.
The lightweight nature of the present invention also permits the assembly of a load-bearing, insulating building wall using only a single workman without the need for lifting equipment. Load-bearing, insulating panels of a size and weight which can be carried by a single workman are set upright and secured in place one at a time to progressively form a wall.